Composition for producing a thermal insulation coating

ABSTRACT

The invention relates to a composition for producing a heat-insulating coating comprising at least one radiation-absorbing compound and at least one IR-reflector component, to a heat-insulating coating comprising this oriented, cured composition, and to a process for producing said coating.

The present invention relates to a composition for producing aheat-insulating coating comprising at least one radiation-absorbingcompound and at least one IR-reflector component, to a heat-insulatingcoating comprising this oriented, cured composition, and to a processfor producing said coating.

The problem of screening against thermal radiation is important inparticular in connection with the insulation of residential, office orindustrial buildings, in particular in connection with buildings with agenerous expanse of windows, but also in connection with means oftransport, such as cars and public transport vehicles.

The use of materials which substantially reflect thermal radiation forheat insulation, especially for screening against thermal radiation inthe wavelength range between 800 nm and 2000 nm, is known. Thesematerials may be, for example, cholesteric IR-reflecting layers.

When substances exhibiting shape anisotropy are heated, it is possiblefor liquid-crystalline phases known as mesophases to occur. Theindividual phases differ in the spatial arrangement of the centers ofmass of the molecules, on the one hand, and in the arrangement of themolecules with respect to the longitudinal axes, on the other hand (G.W. Gray, P. A. Winsor, Liquid Crystals and Plastic Crystals, EllisHorwood Limited, Chichester, 1974).

The nematic liquid-crystalline phase has a parallel orientation of thelongitudinal axes of the molecules (one-dimensional ordered state).Provided that the molecules forming the nematic phase are chiral, theresult is a chiral nematic (cholesteric) phase in which the longitudinalaxes of the molecules form a helical superstructure perpendicularthereto (H. Baessler, Festkörperprobleme XI, 1971). The distance betweentwo imaginary layers in which the orientation of the longitudinal axesof the molecules is the same is known as pitch.

The chiral moiety can either be present in the liquid-crystallinemolecule itself or can be added to the nematic phase as a dopant,thereby inducing the chiral nematic phase. This phenomenon was firstinvestigated on cholesterol derivatives (e.g. H. Baessler, M. M. Labes,J. Chem. Phys. 52, 631 (1970)). The pitch and thus the wavelength rangeof the selectively reflected radiation of a chiral nematic layer can bevaried by altering the concentration of a chiral dopant.

The chiral nematic phase has special optical properties: a high opticalrotation and a pronounced circular dichroism resulting from selectivereflection of circularly polarized light within the chiral nematiclayers. Chiral nematic systems of this type have interestingpossibilities for practical use.

Transparent heat-insulating coatings are known. For example, EP-A-727306describes a laminated glass consisting of two glass plates and aninterlayer in which ultra-fine particles are dispersed. The interlayeris used for heat-insulating and UV absorption.

JP-A-281403/92 describes a laminate consisting of a transparent plate, acoating which reflects IR radiation over a broad wavelength range, and acholesteric liquid-crystal wavelength filter which selectively reflectsnear-IR wavelengths and is highly transparent for visible light. The useof IR-absorbing components is not mentioned.

DE-A-19817069 describes IR-reflecting color compositions consisting ofan IR-reflecting cholesteric liquid-crystalline polymer andlight-absorbing colorants. Colorants are defined as compounds having anabsorption maximum in the range from 350 to 750 nm. The use ofIR-absorbing components is not mentioned.

WO-A-99/19267 describes heat-insulating coatings comprising one or morecholesteric IR-reflecting layers. The coating is transparent andcolorless. However, effective heat-insulation can only be achieved byusing a plurality of cholesteric layers.

It is an object of the present invention to provide an effective, tintedheat-insulating coating which is as thin as possible.

We have found that this object is achieved by a composition forproducing a heat-insulating coating, which comprises

-   i) at least one radiation-absorbing tert-alkylphenoxy-substituted    polycyclic compound A of the general formula I    -   where    -   P is a conjugated polycyclic radical which is stable to bases        and nucleophiles, optionally bears aryl substituents and        contains no group from the group consisting of —CO—NH—CO—, —COOH        and —CO—O—CO—;    -   R is C₁-C₈-alkyl, whose carbon chain may be interrupted by one        of more groups selected from the group consisting of —O—, —S—,        —NR¹—, —CO— and —SO₂— and which may be monosubstituted or        polysubstituted by identical or different radicals selected from        the group consisting of C₁-C₆-alkoxy and a 5- to 7-membered        heterocyclic radical which is attached via a nitrogen atom and        may contain further heteroatoms and/or may be aromatic; or R is        C₅-C₈-cycloalkyl, whose carbon framework may be interrupted by        one or more groups selected from the group consisting of —O—,        —S—, —NR¹—, —CO— and —SO₂— and which may be monosubstituted or        polysubstituted by C₁-C₆-alkyl;    -   R¹ is hydrogen or C₁-C₆-alkyl;    -   Hal is chlorine and/or bromine;    -   m is from 0 to 15; and    -   n is from 1 to 16, subject to the proviso that the sum m+n is        ≦16 and    -   ii) at least one curable IR-reflecting component B which        comprises    -   a) at least one achiral nematic polymerizable monomer and at        least one chiral polymerizable monomer;    -   b) at least one cholesteric polymerizable monomer;    -   c) at least one cholesteric crosslinkable polymer; or    -   d) at least one cholesteric polymer in a polymerizable diluent.

The IR-reflecting property of component B is due to the fact that, afterorientating and curing component B, at least part of the orientedcholesteric polymers obtainable by polymerizing the monomers a) or b) orat least part of the oriented polymers c) or d) has a helicalsuperstructure pitch which corresponds to a wavelength in the IRspectral range.

In the context of the present invention, curing means both thepolymerization of monomers and the crosslinking of polymers.

Radiation-absorbing compounds A are meant to be those which absorb inthe infrared (IR) spectral range, i.e. in the spectral range having awavelength of from >750 nm to about 1 mm, preferably from 751 nm toabout 2000 nm, and/or in the visible spectral range, i.e. in thespectral range having a wavelength of from 350 to 750 nm, preferablyfrom 550 to 750 nm, and/or in the ultraviolet (UV) spectral range, i.e.in the spectral range having a wavelength of from 10 nm to <350 nm,preferably from 100 nm to 349 nm. Preferably, the compounds A absorb inthe infrared spectral range, in particular from 751 to 2000 nm, and/orin the visible spectral range, in particular from 550 to 750 nm.Particularly preferably, the compounds A absorb in the infrared spectralrange, in particular from 751 to 2000 nm, and in the visible spectralrange, in particular from 550 to 750 nm.

The compounds A may be used as pure substances or as mixtures ofpositional isomers or as mixtures of substances.

The compounds A of formula I are described, for example, in PCTapplication PCT/EP 02/03279 and are based on a conjugated polycyclicradical P which is stable to bases and nucleophiles under the reactionconditions. In particular, the radical P contains no group from thegroup consisting of —CO—NH—CO—, —COOH and —CO—O—CO—.

P can bear aryl substituents that are resistant to base attack, forexample unsubstituted or alkyl- and/or alkoxy-substituted aryl,especially phenyl, or hetaryl, such as 2-, 3- and 4-pyridyl andpyrimidyl. These aryl substituents can either be attached directly tothe ring structure or, in the case of the hereinbelow recited polycyclicimides, to the imide nitrogen atoms.

The tert-alkylphenoxy radical(s) in such aryl-substituted radicals P canalso be attached to P via the aryl substituents, for example via the 4-or 3,5-positions of the phenyl radical in the case ofdiphenyldiketopyrrolopyrrole orN,N′-diphenylperylene-3,4:9,10-tetracarboxylic diimide.

Preferably P is a base-stable radical selected from the group consistingof naphthalenes, anthracenes, phenanthrenes, tetracenes, perylenes,terrylenes, quaterrylenes, pentarylenes and hexarylenes, anthraquinones,indanthrones, N-substituted naphthalene-1,8-dicarboxylic monoimides(hereinafter referred to as naphthalmonoimides for short),N,N′-disubstituted naphthalene-1,8:4,5-tetracarboxylic diimides(naphthalimides for short), N-substituted perylene-3,4-dicarboxylicmonoimides (perylmonoimides for short), N,N′-disubstitutedperylene-3,4:9,10-tetracarboxylic diimides (perylimides for short),N,N′-disubstituted terrylene-3,4:11,12-tetracarboxylic diimides(terrylimides for short), N,N′-disubstitutedquaterrylene-3,4:13,14-tetracarboxylic diimides (quaterrylimides forshort), acridines, carbazoles, dibenzofurans, dinaphthofurans,benzimidazoles, benzthiazoles, phenazines, dioxazines, quinacridones,metal phthalocyanines, metal naphthalocyanines, metal porphyrins,cumarins, dibenzofuranones, dinaphthofuranones, benzimidazolones, indigocompounds, thioindigo compounds, quinophthalones, naphthoquinophthalonesand diketopyrrolopyrroles.

Particular preference is given to P from the group consisting ofnaphthalenes, quinacridones, diketopyrrolopyrroles, dioxazines,indanthrones, metal phthalocyanines, metal naphthalocyanines,naphthalmonoimides, perylmonoimides, perylimides, terrylimides andquaterrylimides, and the metal phthalocyanines, metal naphthalocyanines,metal porphyrins, terrylimides and quaterrylimides are very particularlypreferred. From these, the quaterrylimides are especially preferred.

The tert-alkylphenoxy radicals characterizing the compounds I and alsoany halogen atoms present in addition may be attached directly or, asdescribed above, via any aryl substituents to the ring structure of theradicals P. It will be appreciated that both forms of attachment canoccur in one and the same compound I. Larger radicals P, such asperylmonoimides, perylimides, terrylimides and quaterrylimides, bear thetert-alkylphenoxy radicals preferably directly on the ring structure orhave at least directly attached tert-alkylphenoxy radicals in additionto arylene-attached tert-alkylphenoxy radicals.

Depending on the size of the conjugated ring system, the compounds Icontain from at least 1 to 16 (n: 1 to 16), in particular from 2 to 8,tert-alkylphenoxy radicals.

Generally suitable and prefered ranges for m+n will now be mentioned byway of example for particularly preferred radicals P: naphthalene: 1-4,in particular 1-2; quinacridones: 1-8, in particular 2-4;diketopyrrolopyrroles: 1-6, in particular 2-4; dioxazines: 1-8, inparticular 2-4; indanthrones: 1-6, in particular 2-4; metalphthalocyanines: 1-16, in particular 4-8; metal naphthalocyanines: 1-16,in particular 8-16; naphthalmonoimides: 1-4, in particular 1-2;perylmonoimides: 1-6, in particular 1-3; perylimides: 1-8, in particular2-6; terrylimides: 1-12, in particular 2-8; quaterrylimides: 1-14, inparticular 2-8.

When the radicals P contain additional aryl substituents not used forattaching tert-alkylphenoxy radicals, the maximum for the sum m+ndecreases accordingly.

The tert-alkylphenoxy radicals and any Hal substituents are preferablyrandomly distributed across the radical P.

Suitable examples of the radicals R and R¹ of the formula I and fortheir substituents will now be recited:

-   C₁-C₆-alkyl is, for example, methyl, ethyl, propyl, isopropyl,    butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl,    neopentyl, tert-pentyl, hexyl and 2-methylpentyl. In addition to    these radicals, C₁-C₈-alkyl is, for example, heptyl, 1-ethylpentyl,    octyl, 2-ethylhexyl and isooctyl.-   C₁-C₈-alkyl whose carbon chain may be interrupted by one or more    groups —O— is, for example, 2-methoxyethyl, 2-ethoxyethyl,    2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2- and    3-methoxypropyl, 2- and 3-ethoxypropyl, 2- and 3-propoxypropyl, 2-    and 3-butoxypropyl, 2- and 4-methoxybutyl, 2- and 4-ethoxybutyl, 2-    and 4-propoxybutyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl, 4,8-dioxanonyl,    3,7-dioxaoctyl, 3,7-dioxanonyl, 4,7-dioxaoctyl, 4,7-dioxanonyl, 2-    and 4-butoxybutyl, 4,8-dioxadecyl, 3,6,9-trioxadecyl and    3,6,9-trioxaundecyl.

C₁-C₈-alkyl whose carbon chain may be interrupted by one or more groups—S— is, for example, 2-methylthioethyl, 2-ethylthioethyl,2-propylthioethyl, 2-isopropylthioethyl, 2-butylthioethyl, 2- and3-methylthiopropyl, 2- and 3-ethylthiopropyl, 2- and 3-propylthiopropyl,2- and 3-butylthiopropyl, 2- and 4-methylthiobutyl, 2- and4-ethylthiobutyl, 2- and 4-propylthiobutyl, 3,6-dithiaheptyl,3,6-dithiaoctyl, 4,8-dithianonyl, 3,7-dithiaoctyl, 3,7-dithianonyl,4,7-dithiaoctyl, 4,7-dithianonyl, 2- and 4-butylthiobutyl,4,8-dithiadecyl, 3,6,9-trithiadecyl and 3,6,9-trithiaundecyl.

-   C₁-C₈-alkyl whose carbon chain may be interrupted by one or more    groups —NR¹— is, for example, 2-monomethyl- and    2-monoethylaminoethyl, 2-dimethylaminoethyl, 2- and    3-dimethylaminopropyl, 3-monoisopropylaminopropyl, 2- and    4-monopropylaminobutyl, 2- and 4-monomethylaminobutyl,    6-methyl-3,6-diazaheptyl, 3,6-dimethyl-3,6-diazaheyptyl,    3,6-diazaoctyl, 3,6-dimethyl-3,6-diazaoctyl,    9-methyl-3,6,9-triazadecyl, 3,6,9-trimethyl-3,6,9-triazadecyl,    3,6,9-triazaundecyl and 3,6,9-trimethyl-3,6,9-triazaundecyl.-   C₁-C₈-alkyl whose carbon chain may be interrupted by one or more    groups —CO— is, for example, propan-2-on-1-yl, butan-3-on-1-yl,    butan-3-on-2-yl and 2-ethylpentan-3-on-1-yl.-   C₁-C₈-alkyl whose carbon chain may be interrupted by one or more    groups —SO₂— is, for example, 2-methylsulfonylethyl,    2-ethylsulfonylethyl, 2-propylsulfonylethyl,    2-isopropylsulfonylethyl, 2-butylsulfonylethyl, 2- and    3-methylsulfonylpropyl, 2- and 3-ethylsulfonylpropyl, 2- and    3-propylsulfonylpropyl, 2- and 3-butylsulfonylpropyl, 2- and    4-methylsulfonylbutyl, 2- and 4-ethylsulfonylbutyl, 2- and    4-propylsulfonylbutyl and 4-butylsulfonylbutyl.-   C₁-C₆-alkoxy is, for example, methoxy, ethoxy, propoxy, isopropoxy,    butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy,    neopentoxy, tert-pentoxy and hexoxy.

The 5- to 7-membered heterocyclic radical which is attached via anitrogen atom and may contain further heteroatoms and/or may bearomatic, is, for example, pyrrole, pyrazole, imidazole, triazole,pyrrolidine, pyrazoline, pyrazolidine, imidazoline, imidazolidine,pyridine, pyridazine, pyrimidine, pyrazine, triazine, piperidine,piperazine, oxazole, isooxazole, thiazole, isothiazole, indole,quinoline, isoquinoline or quinaldine.

C₅-C₈-cycloalkyl, whose carbon framework may be interrupted by one ormore groups selected from the group consisting of —O—, —S—, NR¹—, —CO—and —SO₂— and which may be monosubstituted or polysubstituted byC₁-C₆-alkyl, is, for example, cyclopentyl, 2- and 3-methylcyclopentyl,2- and 3-ethylcyclopentyl, cyclohexyl, 2-, 3- and 4-methylcyclohexyl,2-, 3- and 4-ethylcyclohexyl, 3- and 4-propylcyclohexyl, 3- and4-isopropylcyclohexyl, 3- and 4-butylcyclohexyl, 3- and4-sec-butylcyclohexyl, 3- and 4-tert-butylcyclohexyl, cycloheptyl, 2-,3- and 4-methylcycloheptyl, 2-, 3- and 4-ethylcycloheptyl, 3- and4-propylcycloheptyl, 3- and 4-isopropylcycloheptyl, 3- and4-butylcycloheptyl, 3- and 4-sec-butylcycloheptyl, 3- and4-tert-butylcycloheptyl, cyclooctyl, 2-, 3-, 4- and 5-methylcyclooctyl,2-, 3-, 4- and 5-ethylcyclooctyl, 3-, 4- and 5-propylcyclooctyl,2-dioxanyl, 4-morpholinyl, 2- and 3-tetrahydrofuryl, 1-, 2- and3-pyrrolidinyl and 1-, 2-, 3- and 4-piperidyl.

Examples of preferred tert-alkylphenoxy radicals arep-(1,1-dimethylpropyl)phenoxy, p-(1,1-dimethylbutyl)phenoxy,p-(1,1-dimethylpentyl)phenoxy, p-(1,1,3,3-tetramethylbutyl)-phenoxy,p-(2-cyclopentyl-1,1-dimethylethyl)phenoxy,p-(2-cyclohexyl-1,1-dimethylethyl)phenoxy,p-(2-cycloheptyl-1,1-dimethylethyl)phenoxy andp-(1,1-dimethyl-2-(4-morpholinyl) ethyl)phenoxy. Particular preferenceis given to p-(1,1,3,3-tetramethylbutyl)phenoxy.

The particularly preferred naphthalmonoimides, perylmonoimides,perylimides, terrylimides and quaterrylimides bear in particular thefollowing base-stable substituents R² on the imide nitrogen atoms:

-   C₁-C₃₀-alkyl, whose carbon chain may be interrupted by one or more    groups selected from —O—, —S—, —NR¹—, —CO— and —SO₂—, and which may    be monosubstituted or polysubstituted by identical or different    radicals selected from C₁-C₆-alkoxy and a 5- to 7-membered    heterocyclic radical which is attached via a nitrogen atom and may    contain further heteroatoms and/or may be aromatic;-   C₅-C₈-cycloalkyl, whose carbon framework may be interrupted by one    or more groups selected from the group consisting of —O—, —S—,    —NR¹—, —CO— and —SO₂—, and which may be monosubstituted or    polysubstituted by C₁-C₆-alkyl;-   aryl or heteroaryl, such as phenyl, naphthyl, anthracenyl,    phenantrenyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, thiazolyl,    pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolyl, quinolinyl,    isoquinolinyl or quinaldinyl, where each of these radicals may be    monosubstituted or polysubstituted by C₁-C₁₈-alkyl, C₁-C₆-alkoxy,    cyano, —CONH—R¹ and/or —NH—COR¹.

The following radicals may be specifically mentioned by way of examplefor these substituents in addition to the radicals already mentioned:

-   in addition to the abovementioned alkyl radicals, C₁-C₃₀-alkyl is,    for example, nonyl, isononyl, decyl, isodecyl, undecyl, dodecyl,    tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl,    heptadecyl, octadecyl, nonadecyl and eicosyl (the designations    isononyl, isodecyl and isotridecyl as well as the abovementioned    designation isooctyl are trivial names derived from the alcohols    obtained by the oxo process);-   C₁-C₃₀-alkyl interrupted by the group —O— or —S— is, for example,    3,6,9-trioxadodecyl, 3,6,9,12-tetraoxatridecyl and    3,6,9,12-tetraoxatetradecyl; 3,6,9-trithiadodecyl,    3,6,9,12-tetrathiatridecyl and 3,6,9,12-tetrathiatetradecyl;-   the substituents —CO—NHR¹ and —NH—COR¹ are, for example, carbamoyl,    methylaminocarbonyl, ethylaminocarbonyl, propylaminocarbonyl,    butylaminocarbonyl, pentylaminocarbonyl, hexylaminocarbonyl,    heptylaminocarbonyl, octylaminocarbonyl, nonylaminocarbonyl and    decylaminocarbonyl; formylamino, acetylamino and propionylamino;-   aryl or heteroaryl which may be monosubstituted or polysubstituted    by C₁-C₁₈-alkyl, C₁-C₆-alkoxy, cyano, —CONH—R¹ and/or —NH—COR¹ is,    for example, 2-, 3- and 4-methylphenyl, 2,4-, 2,5-, 3,5- and    2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2-, 3- and 4-ethylphenyl,    2,4-, 2,5-, 3,5- and 2,6-diethylphenyl, 2,4,6-triethylphenyl, 2-, 3-    and 4-propylphenyl, 2,4-, 2,5-, 3,5- and 2,6-dipropylphenyl,    2,4,6-tripropylphenyl, 2-, 3- and 4-isopropylphenyl, 2,4-, 2,5-,    3,5- and 2,6-diisopropylphenyl, 2,4,6-triisopropylphenyl, 2-, 3- and    4-butylphenyl, 2,4-, 2,5-, 3,5- and 2,6-dibutylphenyl,    2,4,6-tributylphenyl, 2-, 3- and 4-isobutylphenyl, 2,4-, 2,5-, 3,5-    and 2,6-diisobutylphenyl, 2,4,6-triisobutylphenyl, 2-, 3- and    4-sec-butylphenyl, 2,4-, 2,5-, 3,5- and 2,6-di-sec-butylphenyl,    2,4,6-tri-sec-butylphenyl, 2-, 3- and 4-tert-butylphenyl, 2,4-,    2,5-, 3,5- and 2,6-di-tert-butylphenyl and    2,4,6-tri-tert-butylphenyl; 2-, 3- and 4-methoxyphenyl, 2,4-, 2,5-,    3,5- and 2,6-dimethoxyphenyl, 2,4,6-trimethoxyphenyl, 2-, 3- and    4-ethoxyphenyl, 2,4-, 2,5-, 3,5- and 2,6-diethoxyphenyl,    2,4,6-triethoxyphenyl, 2-, 3- and 4-propoxyphenyl, 2,4-, 2,5-, 3,5-    and 2,6-dipropoxyphenyl, 2-, 3- and 4-isopropoxyphenyl, 2,4-, 2,5-,    3,5- and 2,6-diisopropoxyphenyl and 2-, 3- and 4-butoxyphenyl; 2-,    3- and 4-cyanophenyl; 3- and 4-carboxamidophenyl, 3- and    4-N-(methyl)carboxamidophenyl and 3- and    4-N-(ethyl)carboxamidophenyl; 3- and 4-acetylaminophenyl, 3- and    4-propionylaminophenyl and 3- and 4-butyrylaminophenyl.

Particularly preferred compounds A are those in which P is anN,N′-disubstituted quaterrylene-3,4:13,14-tetracarboxylic diimide offormula II

where R² is identical to the abovementioned, base-stable imidonitrogenatom substituents.

In particularly preferred compounds A of formula I in which P is aquaterrylimide II,

-   R is preferably H, methyl, ethyl, propyl, isopropyl, butyl,    tert-butyl, cyclopentyl, cyclohexyl, cycloheptyl or morpholinyl,    particularly preferably H, methyl, ethyl, butyl or tert-butyl and    especially tert-butyl;-   R² is preferably substituted phenyl, particularly preferably phenyl    substituted by from one to three C₁-C₄-alkyl radicals and especially    2,6-diisopropylphenyl;-   n is preferably from 2 to 10, particularly preferably from 4 to 8    and especially 6; and-   m is preferably from 0 to 4, particularly preferably from 0 to 2 and    in particular 0.

The n tert-alkylphenoxy substituents and the m Hal substituents arepreferably randomly distributed across the quaterrylene system. It isparticularly preferred for the same number of substituents to be presenton the two sides of an imaginary axis between the two imide nitrogenatoms.

The compounds of the formula I can be prepared by a process, whichcomprises reacting a halide of the general formula III

in an inert basic nitrogen-containing solvent and in the presence of abase with a tert-alkylphenol of the general formula IV

Useful inert basic nitrogen-containing solvents are in particular polarsolvents, especially nitrogen-containing heterocycles, such as pyridine,pyrimidine, quinoline, isoquinoline, quinaldine and preferablyN-methylpyrrolidone, and also carboxamides, such asN,N-dimethylformamide and N,N-dimethylacetamide.

The solvent quantity depends on the solubility of the halide III and isusually in the range from 2 to 40 g, preferably from 4 to 25 g, ofsolvent per g of halide III.

Useful bases are in particular non-nucleophilic or only weaklynucleophilic compounds. Examples of such bases are alkali metalhydroxides, such as potassium hydroxide and sodium hydroxide, alkalimetal carbonates, such as potassium carbonate and sodium carbonate, andalkali metal alkoxides of tertiary alcohols, such as lithiumtert-butoxide, sodium tert-butoxide and potassium tert-butoxide, whichare used in anhydrous form.

In general, from 0.8 to 1.5, preferably from 1.0 to 1.2, molarequivalents of base are used per mole of halogen atom to be substituted.

The halides III used as starting materials are generally known orobtainable according to known methods by reacting the unhalogenatedconjugated polycyclic compounds with halogenating agents, in particularthe elemental halogens. Halides III which contain halogen atoms attachedto aryl substituents are known to be generally obtainable byintroduction of the halogenated aryl radicals into the polycyclicsystem.

The molar ratio of halide III to phenol IV depends on the number ofhalogen atoms to be substituted. In general, from 1 to 2, preferablyfrom 1 to 1.3, mol of phenol IV is used per mole of halogen atom to bereplaced in halide III.

The reaction temperature is usually in the range from 50 to 200° C.,preferably from 60 to 140° C.

It is advisable for the reaction to be carried out under protective gas,for example nitrogen or argon.

The reaction time depends on the reactivity of the halide III and isabout 2-48 h.

Varying the reaction conditions—amount of phenol IV and base and thereaction temperature—advantageously provides control over the halogenreplacement, so that it is no problem to prepare not only products I inwhich all the halogen atoms have been replaced (m=0) but also products Iwhich still contain halogen. If desired, the halogen can subsequently beremoved from the product I. Thus, a single starting material III can beused to prepare various products I as desired.

For component B, preferable monomers from the group a) are described inWO 99/19267 and in German patent application P 10203938.0, the fullcontent of which is incorporated herein by reference. The achiralnematic polymerizable monomer from group a) is preferably difunctionallypolymerizable and preferably corresponds to the general formula VZ¹-(Y¹-A¹)_(v)-Y²-M-Y³-(A²-Y⁴)_(w)-Z²  (V)where

-   Z¹ and Z² are identical or different reactive groups via which a    polymerization can take place, or radicals which contain such    reactive groups, the reactive groups being C═C double bonds, C≡C    triple bonds, or oxirane, thiirane, azirane, cyanate, thiocyanate,    isocyanate, carboxyl, hydroxyl or amino groups, C═C double bonds    being particularly preferred;-   Y¹, Y², Y³ and Y⁴ are each, independently of one another, a chemical    bond, O, S, —CO—O—, —O—CO—, —O—CO—O—, —CO—S—, —S—CO—, —CO—N(R³)—,    —N(R³)—CO—, —N(R³)—CO—O—, —O—CO—N(R³)—, —N(R³)—CO—N(R³)—, —CH₂—O—,    —O—CH₂—, preferably —CO—O—, —O—CO— or —O—CO—O—,-   R³ being hydrogen or C₁-C₄-alkyl;-   A¹ and A² are identical or different spacers, for example linear    C₂-C₃₀-alkylene groups, preferably C₂-C₁₂-alkylene groups, which may    be interrupted by oxygen, sulfur or unsubstituted or monosubstituted    nitrogen, where these interrupting groups may not be adjacent;    suitable amine substituents comprising C₁-C₄-alkyl groups, where the    alkylene chains may be substituted by fluorine, chlorine, bromine,    cyano, methyl or ethyl; and where A¹ and A² are particularly    preferably —(CH₂)—_(n) where n=2 to 6;-   v and w are 0 or 1;-   M is a mesogenic group which is preferably of the general formula    VI:    (T-Y⁵)_(m)-T  (VI)    where-   T represents identical or different divalent isocycloaliphatic,    heterocycloaliphatic, isoaromatic or heteroaromatic radicals,    preferably 1,4-bonded unsubstituted or mono- to polysubstituted, for    example mono- to tetrasubstituted, benzene rings,    where-   R⁴ is fluorine, chlorine, bromine, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy,    C₁-C₂₀-alkylcarbonyl, C₁-C₂₀-alkylcarbonyloxy, hydroxyl, nitro, CHO    or CN, preferably chlorine, bromine or C₁-C₄-alkyl and in particular    methyl; and-   n is an integer from 0 to 4, preferably from 0 to 2, in particular 0    or 1;-   Y⁵ are identical or different bridge members —CO—O—, —O—CO—,    —CH₂—O—, —O—CH₂—, —CO—S—, —S—CO—, —CH₂—S—, —S—CH₂, —CH═N— or —N═CH—    or a direct bond, preferably —CO—O— or —O—CO—, and-   m is an integer from 0 to 3, preferably 0, 1 or 2.

The mesogenic group preferably contains a substituted 1,4-dioxybenzenebuilding block, in particular a methyl-substituted 1,4-dioxybenzenebuilding block.

Particularly preferred mesogenic groups have the following structuresVII:

where

-   R⁴ is fluorine, chlorine, bromine, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy,    C₁-C₂₀-alkylcarbonyl, C₁-C₂₀-alkylcarbonyloxy, hydroxyl, nitro, CHO    or CN and-   n is an integer from 0 to 4.

In the mesogenic group VII, R⁴ is particularly preferably chlorine,bromine or C₁-C₄-alkyl, in particular methyl, and n is from 0 to 2, inparticular 0 or 1, especially 1.

Very particularly preferred mesogenic groups have the followingstructure VIII:

The chiral polymerizable monomer from group a) is preferably of formulaIX[(Z¹-Y¹)_(o)-A³-Y²-M-Y³]_(n)X[Y³-M-Y²-A⁴-(Y¹-Z¹)_(p)]_(m)  (IX)where

-   Z¹, Y¹, Y², Y³ and M are as defined above,-   o, p are 0 or 1, subject to the proviso that o and p may not both be    0,-   A³ and A⁴ are identical or different and-   A³ is as defined for A¹ if o=1 or    -   is a linear C₂-C₃₀-alkylene group, preferably C₂-C₁₂-alkylene        group which may be interrupted by oxygen, sulfur or        unsubstituted or monosubstituted nitrogen, where these        interrupting groups may not be adjacent; suitable amine        substituents comprising C₁-C₄-alkyl groups which may be        substituted by fluorine, chlorine, bromine, cyano, methyl or        ethyl and where A³ is particularly preferably CH₃        CH₂)₁ groups where l=1 to 7, if o=0;-   A⁴ is as defined for A¹ if p=1 or    -   is a linear C₂-C₃₀-alkyl group, preferably C₂-C₁₂-alkyl group        which may be interrupted by oxygen, sulfur or unsubstituted or        monosubstituted nitrogen, where these interrupting groups may        not be adjacent; suitable amine substituents comprising        C₁-C₄-alkyl groups which may be substituted by fluorine,        chlorine, bromine, cyano, methyl or ethyl and where A³ is        particularly preferably CH₃        CH₂)₁ groups where l=1 to 7, if p=0;-   n and m are 0, 1 or 2, the sum n+m being equal to 1 or 2, preferably    2; and-   X is a chiral radical.

Of the chiral radicals X of the compounds of the general formula IXparticular preference is given, not least on account of their easieravailability, to those derived from sugars, dinaphthyl or diphenylderivatives and optically active glycols, alcohols or amino acids. Inthe case of sugars, particular mention should be made of pentoses andhexoses and derivatives thereof.

Examples of radicals X are the following structures, the terminal linesin each case denoting the free valencies.

where

-   L¹ is C₁-C₄-alkyl, C₁-C₄-alkoxy, halogen, COOR⁵, OCOR⁵, NHCOR⁵ and    R⁵ is C₁-C₄-alkyl or hydrogen.

Particular preference is given to

Also suitable are chiral groups which have the following structures:

In the above definition of the groups A¹, A², A³, A⁴, R³, R⁴, R⁵ and L¹,C₁-C₂₀-alkyl is in particular methyl, ethyl, n-propyl, isopropyl,n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl,nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl,hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl;

-   C₁-C₄-alkyl is in particular methyl, ethyl, n-propyl, isopropyl,    n-butyl, sec-butyl, isobutyl or tert-butyl;-   C₁-C₂₀-alkoxy is in particular alkoxy whose alkyl radical    corresponds to the abovementioned C₁-C₂₀-alkyl groups; and-   C₂-C₃₀-alkylene is in particular alkylene which correspond to the    bivalent radical of the abovementioned C₂-C₂₀-alkyl groups, or is a    linear C₂₁-C₃₀-homolog.

In a particular embodiment, the nematic achiral polymerizable monomerhas the following structural formula X

In a further particular embodiment, the chiral polymerizable monomer hasthe following structural formula XI or XII

The proportion of achiral nematic monomer to chiral monomer is selectedsuch that the polymer resulting from these monomers, followingorientation, has a helical superstructure pitch which corresponds to awavelength in the IR spectral range. The proportion depends on the typeof nematic and chiral monomers and must be determined for eachindividual case.

Alternatively, at least one cholesteric polymerizable monomer of groupb) can be used as component B.

Preferred monomers of group b) are described in DE-A 19602848, the truecontent of which is incorporated herein by reference. In particular, themonomers b) comprise at least one cholesteric polymerizable monomer ofthe formula XIII(Z¹-Y¹-A¹-Y²-M¹-Y³)_(n)X  (XIII)

The variables are as defined for the monomers of group a). The preferredembodiments apply correspondingly.

Alternatively, at least one cholesteric crosslinkable polymer of groupc) may be used as component B.

Preferred polymers of group c) are cholesteric cellulose derivatives asdescribed in DE-A-197 136 38, in particular cholesteric mixed esters of

-   (1) hydroxyalkyl ethers of cellulose with-   (2) saturated, aliphatic or aromatic carboxylic acids and-   (3) unsaturated mono- or dicarboxylic acids.

Particular preference is given to mixed esters in which the hydroxyalkylradicals of component (1) that are attached via ether functions comprisestraight-chain or branched C₂-C₁₀-hydroxyalkyl radicals, in particularhydroxypropyl and/or hydroxyethyl radicals. Component (1) of thesuitable mixed esters preferably has a molecular weight of from about500 to about 1 million. Preferably, the anhydroglucose units of thecellulose are etherified with hydroxyalkyl radicals in an average molardegree of substitution of from 2 to 4. The hydroxyalkyl group in thecellulose can be identical or different. Up to 50% of them can also bereplaced by alkyl groups (in particular C₁-C₁₀-alkyl groups). Oneexample of such a compound is hydroxypropylmethylcellulose.

Compounds which can be used as component (2) of the suitable mixedesters are straight-chain aliphatic C₁-C₁₀-carboxylic acids, inparticular C₂-C₆-carboxylic acids, branched aliphatic C₄-C₁₀-carboxylicacids, in particular C₄-C₆-carboxylic acids or straight-chain orbranched halocarboxylic acids. Component (2) can also comprise benzoicacid or aliphatic carboxylic acids bearing aromatic substituents, inparticular phenylacetic acid. Particularly preferably, component (2) isselected from acetic, propionic, n-butyric, isobutyric and n-valericacid, in particular from propionic, 3-chloropropionic, n-butyric andisobutyric acid.

Component (3) is preferably selected from unsaturated C₃-C₁₂-mono- ordicarboxylic acids or monoesters of such a dicarboxylic acid, inparticular α,β-ethylenically unsaturated C₃-C₆-mono- or dicarboxylicacids or monoesters of the dicarboxylic acids.

Particularly preferably, component (3) of the suitable mixed esters isselected from acrylic, methacrylic, crotonic, vinylacetic, maleic,fumaric and undecenoic acid, especially from acrylic and methacrylicacid.

Component (1) is preferably esterified with component (2) and (3) in anaverage molar degree of substitution of from 1.5 to 3, in particularfrom 1.6 to 2.7, particularly preferably from 2.3 to 2.6. Preferablyabout 1 to 30%, in particular from 1 to 20% or 1 to 10%, particularlypreferably from about 5 to 7%, of the OH groups of component (1) areesterified with component (3).

The proportion of component (2) to component (3) determines thereflection wavelength of the polymer.

Suitable polymers of group c) are furthermore the propargyl-terminatedcholesteric polyesters or polycarbonates described in DE-A-197 17 371.

Among these compounds, preference is given to polyesters orpolycarbonates having at least one terminal propargyl group of theformula R⁶C≡C—CH₂—, where R⁶ is H, C₁-C₄-alkyl, aryl or Ar—C₁-C₄-alkyl(for example benzyl or phenethyl) which is attached to the polyesters orpolycarbonates directly or via a linker. The linker is preferablyselected from

-   -   (the propargyl group is attached to Z),        where R⁷ is H, C₁-C₄-alkyl or phenyl, Z is O, S or NR⁸, and R⁸        is H, C₁-C₄-alkyl or phenyl.

In the polyesters, the terminal propargyl group is preferably attachedvia

The polyesters preferably comprise

-   (4) at least one aromatic or araliphatic dicarboxylic acid unit    and/or at least one aromatic or araliphatic hydroxycarboxylic acid    unit and-   (5) at least one diol unit.

Preferred dicarboxylic acid units are those of the formula

in particular those of the formula

where each of the phenyl groups or the naphthyl group may contain 1, 2or 3 substituents selected independently of one another from the groupconsisting Of C₁-C₄-alkyl, C₁-C₄-alkoxy, halogen and phenyl, and where,in the above formulae

-   W is NR⁹, S, O, (CH₂)_(r)O(CH₂)_(q), (CH₂)_(s) or a single bond,-   R⁹ is alkyl or hydrogen,-   s is an integer from 1 to 15, and-   r and q are each, independently of one another, an integer from 0 to    10.

Preferred hydroxycarboxylic acid units are those of the formula

where each phenyl group or the naphthyl group may contain 1, 2 or 3substituents selected independently of one another from the groupconsisting of C₁-C₄-alkyl, C₁-C₄-alkoxy, halogen and phenyl.

Preferred diol units are those of the formula

in particular those of the formula

-   -   where, in the above formulae    -   L is alkyl, alkoxy, halogen, COOR¹¹, OCOR¹¹, CONHR¹¹ or NHCOR¹¹,    -   X is S, O, N, CH₂ or a single bond,    -   A is a single bond, (CH₂)_(n), O(CH₂)_(n), S(CH₂)_(n),        NR¹¹(CH₂)_(n),    -   R¹¹ is alkyl or hydrogen,    -   R¹⁰ is hydrogen, halogen, alkyl or phenyl, and    -   n is an integer from 1 to 15.

Preference is given to polyesters comprising at least one dicarboxylicacid unit of the formula

and at least one diol unit of the formula

where R¹⁰ is H, halogen, C₁-C₄-alkyl, in particular CH₃ or C(CH₃)₃, orphenyl.

Further preferred compounds are diesters of the formulaP—Y—B—CO—O-A-O—CO—B—Y—P, where P is a terminal propargyl group of theabove defined formula, Y is O, S or NR¹² (R¹²═C₁-C₄-alkyl), B is

where each phenyl group or the naphthyl group may contain 1, 2 or 3substituents selected independently of one another from the groupconsisting of C₁-C₄-alkyl, C₁-C₄-alkoxy, halogen or phenyl, and A(together with the adjacent oxygen atoms) is one of the abovementioneddiol units.

Particularly preferred diesters are those of the abovementioned formulain which B is

and particular diesters of the formulaHC≡CCH₂O—B—CO—O-A-O—CO—B—OCH₂—C≡CH, wherein

-   -   A is as defined for (6).

Further preferred compounds are polycarbonates comprising at least oneincorporated diol unit of the abovementioned formulae, in particular ofthe formulae

Preference is given here to those polycarbonates which comprise as diolunits at least one mesogenic unit of the formula

at least one chiral unit of the formula

with or without a non-chiral unit of the formula

where R¹⁰ is as defined above and is in particular H or CH₃.

Particularly preferred polycarbonates are those having terminalpropargyl groups of the formula HC≡CCH₂O—R¹³—CO, where R¹³ is

Further suitable polymers of group c) are cholesteric polycarbonateswhich also contain photoreactive groups in a nonterminal position. Suchpolycarbonates are described in DE-A-196 31 658. They are preferably ofthe formula XIV

where the molar ratio w/x/y/z is from about 1 to 20/from about 1 to5/from about 0 to 10/from about 0 to 10. Particular preference is givento a molar ratio w/x/y/z of from about 1 to 5/from about 1 to 2/fromabout 0 to 5/from about 0 to 5.

In the formula XIV,

-   A is a mesogenic group of the formula-   B is a chiral group of the formula-   D is a photoreactive group of the formula    and-   E is a further, non-chiral group of the formula    where, in the above formulae-   L is alkyl, alkoxy, halogen, COOR¹⁵, OCOR¹⁵, CONHR¹⁵ or NHCOR¹⁵,-   X is S, O, N, CH₂ or a single bond,-   R¹⁵ is alkyl or hydrogen,-   A is a single bond, (CH₂)_(n), O(CH₂)_(n), S(CH₂)_(n), NR(CH₂)_(n),-   R¹⁴ is hydrogen, halogen, alkyl or phenyl, and-   n is an integer from 1 to 15.

If R¹⁴ is alkyl or halogen and A is a single bond, or if R¹⁴ is H oralkyl and A is

the groups are solubility-improving groups. Examples thereof are

The preferred chiral component is isosorbide, isomannide and/orisoidide.

The proportion of the chiral diol structural units is preferably withinthe range from 1 to 80 mol % of the total content of diol structuralunits, particularly preferably in the range from 2 to 20 mol %,depending on the desired reflection behavior.

Alternatively, a cholesteric polymer in a polymerizable diluent (groupd)) can be used as component B.

Examples of preferred polymers of group d) are crosslinkable cholestericcopolyisocyanates as described in U.S. Ser. No. 08/834,745, the fullcontent of which is incorporated herein by reference. Suchcopolyisocyanates have repeating units of the formulae

-   -   and, if appropriate, of the formula        here

-   R¹⁶ is a chiral aliphatic or aromatic radical,

-   R¹⁷ is a crosslinkable radical, and

-   R¹⁸ is an achiral radical.

Unless specified otherwise, alkyl (including meanings such as alkoxy,dialkyl, alkylthio etc.) means a branched or unbranched C₁-C₁₂-alkyl,preferably C₃-C₁₂-alkyl, particularly preferably C₄-C₁₀-alkyl, inparticular C₆-C₁₀-alkyl.

R¹⁶ is preferably selected from (chiral) branched or unbranched alkyl,alkoxyalkyl, alkylthioalkyl, cycloalkyl, alkylphenyl or C₃-C₉-epoxyalkylradicals or radicals of esters of C₁-C₆-fatty acids with C₁-C₆-alkanolsor C₃-C₉-dialkylketones. The ester radical can be attached to thenitrogen either via the fatty acid component or via the alkanol radical.The radical R¹⁶ can contain 1, 2 or 3 substituents which are identicalor different and are selected from the group consisting of alkoxygroups, di-C₁-C₄-alkylamino groups, CN, halogen atoms or C₁-C₄-alkylthiogroups.

R¹⁶ is preferably selected from alkyl, alkoxyalkyl, residues of estersof C₁-C₆-fatty acids with C₁-C₆-alkanols, C₃-C₉-dialkylketones andepoxidized C₃-C₉-epoxyalkyl radicals, where R¹⁶ may be substituted by 1or 2 radicals which are identical or different and are selected from thegroup consisting of alkoxy, halogen, CN or CF₃. Preferred substituentsof branched or unbranched alkyl or alkoxy radicals are selected from thegroup consisting of alkoxy groups, halogen atoms or CN; for esters ofC₁-C₆-fatty acids with C₁-C₆-alkanols from the group consisting ofalkoxy groups, halogen atoms, CN or CF₃, and for C₃-C₉-dialkylketonesfrom the group consisting of alkoxy groups, halogen atoms or CN.

In particular, the main chain of the radical R¹⁶ has a length of from 3to 12, especially from 6 to 10, preferably from 6 to 8, members (carbon,oxygen and/or sulfur atoms). Particular reference is given to radicalsR¹⁶ selected from the group consisting of

With very particular preference, component XV of the suitablecopolyisocyanates is derived from 2,6-dimethylheptylisocyanate.

The radical R¹⁷ of the suitable copolyisocyanates is preferably selectedfrom the group consisting of C₃-C₁₁-alkenyl radicals, C₄-C₁₁-vinyletherradicals (=vinyl-C₂-C₉-alkyl ethers), ethylenically unsaturatedC₃-C₁₁-carboxylic acid radicals and esters of ethylenically unsaturatedC₃-C₆-monocarboxylic acids with C₂-C₆-alkanols, where the bond to thenitrogen atom is via the alkanol radical of the ester. Particularlypreferably, the radical is selected from the group consisting of methylacrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutylacrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethylmethacrylate, propyl methacrylate, n-butyl methacrylate, isobutylmethacrylate, 2-ethylhexyl methacrylate, in particular from the groupconsisting of ethyl acrylate and ethyl methacrylate.

The radical R¹⁸ is preferably as defined for R¹⁶. However, it isachiral, i.e. it has no center of chirality or is present as a racemicmixture.

Particularly preferably, the main chain of the radical R¹⁸ has a lengthof from 4 to 12, in particular from 6 to 10, preferably 6 to 8, members(carbon, oxygen and/or sulfur atoms). With very particular preference,component XVII of the copolyisocyanates of the invention is derived fromn-hexyl isocyanate, n-heptyl isocyanate or n-octyl isocyanate.

Components XV, XVI and XVII are preferably present in a molar ratioXV:XVI:XVII of from about 1 to 20:1 to 20:50 to 98, in particular fromabout 5 to 15:5 to 15:65 to 90, particularly preferably about 15:10:75.

The units XV, XVI and XVII can be randomly distributed in the suitablecopolyisocyanates.

A preferred component B of the composition of the invention is a mixtureof at least one achiral nematic polymerizable monomer and a chiralpolymerizable monomer, i.e. group a).

The compound(s) A is/are preferably present in an amount of from 0.01 to20% by weight, particularly preferably from 0.01 to 15% by weight, veryparticularly preferably from 0.01 to 10% by weight, in particular from0.01 to 7% by weight, especially from 0.01 to 5% by weight, based on thetotal weight of component B.

The composition is preferably either an intimate mixture of components Aand B or a solution or dispersion of components A and B in a suitablediluent. The proportion of diluent is preferably from 5 to 95% byweight, particularly preferably from 30 to 80% by weight, in particularfrom 40 to 70% by weight, based on the total weight of the composition.

Suitable diluents for the compounds of groups a) or b) are linear orbranched esters, in particular acetic esters, cyclic ethers and esters,alcohols, lactones, aliphatic and aromatic hydrocarbons, such astoluene, xylene and cyclohexane, and ketones, amides,N-alkylpyrrolidones, in particular N-methylpyrrolidone, and especiallytetrahydrofuran (THF), dioxane and methyl ethyl ketone (MEK).

Examples of suitable diluents for the polymers of group c) are ethersand cyclic ethers, such as tetrahydrofuran or dioxane, chlorinatedhydrocarbons, such as dichloromethane, trichloromethane, carbontetrachloride, dichloroethane, 1,1,2,2-tetrachloroethane,1-chloronaphthalene, chlorobenzene or 1,2-dichlorobenzene. Thesediluents are particularly suitable for polyesters and polycarbonates.Examples of suitable diluents for cellulose derivatives are ethers, suchas dioxane, or ketones, such as acetone. When copolyisocyanates are usedas polymers of group d), it is advisable to use polymerizable diluentsas described in U.S. Ser. No. 08/834,745. Examples of such polymerizablediluents are

-   -   esters of α,β-unsaturated mono- or dicarboxylic acids, in        particular C₃-C₆-mono- or dicarboxylic acids, with        C₁-C₁₂-alkanols, C₂-C₁₂-alkanediols or their C₁-C₆-alkyl ethers        and phenyl ethers, for example acrylates and methacrylates,        hydroxyethyl or hydroxypropyl acrylate or methacrylate and        2-ethoxyethyl acrylate or methacrylate;    -   vinyl-C₁-C₁₂-alkyl ethers, such as vinylethyl, vinylhexyl or        vinyloctyl ether;    -   vinyl esters of C₁-C₁₂-carboxylic acids, such as vinyl acetate,        vinyl propionate, vinyl laurate;    -   C₃-C₉-epoxides, such as 1,2-butylene oxide, styrene oxide;    -   N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide;    -   vinylaromatic compounds, such as styrene, α-methylstyrene,        chlorostyrene, and    -   compounds having two or more crosslinkable groups, such as        diesters of diols (including polyethylene glycols) with acrylic        or methacrylic acids or divinylbenzene.

Examples of preferred polymerizable diluents are 2-ethoxyethyl acrylate,diethylene glycol diacrylate, ethylene glycol dimethacrylate, diethyleneglycol dimethacrylate, triethylene glycol dimethacrylate, diethyleneglycol monomethyl ether acrylate, phenoxyethyl acrylate andtetraethylene glycol dimethacrylate. A particularly preferredpolymerizable diluent is styrene.

The mixtures of groups a), b) or c) may also include polymerizablediluents in small amounts. Preferred polymerizable solvents which can beadded to a), b) or c) are acrylates, in particular acrylates ofrelatively high functionality, such as bis-, tris- or tetraacrylates,and particularly preferably high-boiling oligoacrylates. The preferredamount added is approximately 5% by weight, based on the total weight ofthe mixture.

In order to adjust the viscosity and the leveling behavior, thecomposition of the invention can be mixed with additional components.

For example, it is possible to employ polymeric binders and/or monomericcompounds which can be converted into a polymeric binder bypolymerization. Examples of such compounds are organic-solvent-solublepolyesters, cellulose esters, polyurethanes, silicones and polyether- orpolyester-modified silicones. Particular preference is given to usingcellulose esters such as cellulose acetobutyrate.

The addition of small amounts of suitable leveling agents may also beadvantageous. It is possible to employ from about about 0.005 to 1% byweight, in particular from 0.01 to 0.5% by weight, based on the amountof cholester employed. Examples of suitable leveling agents are glycols,silicone oils and in particular acrylate polymers, such as the acrylatecopolymers Byk 361 or Byk 358 from Byk-Chemie and the modified,silicone-free acrylate polymers Tego flow ZFS 460 from Tego.

The composition may also include UV and weathering stabilizers. Examplesof such additives are derivatives of 2,4-dihydroxybenzophenone,derivatives of 2-cyano-3,3-diphenyl acrylates, derivatives of2,2′,4,4′-tetrahydroxybenzophenone, derivatives ofortho-hydroxyphenylbenzotriazole, salicylic esters,ortho-hydroxyphenyl-s-triazines or sterically hindered amines. Thesesubstances can be employed alone or preferably as mixtures.

If the composition of the invention is to be subjected to photochemicalpolymerization, it may also include customary photoinitiators. Forcuring by electron beams, such initiators are not required. Examples ofsuitable photoinitiators are isobutyl benzoin ether,2,4,6-trimethylbenzoyl diphenyl phosphine oxide, 1-hydroxycyclohexylphenyl ketone,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-furan-1-one, mixtures ofbenzophenone and 1-Hydroxycyclohexyl phenyl ketone,2,2-dimethoxy-2-phenylacetophenone, perfluorinated diphenyltitanocenes,2-methyl-1-(4-[methylthio]phenyl)-2-(4-morpholinyl)-1-propanone,2-hydroxy-2-methyl-1-phenylpropan-1-one,4-(2-hydroxyethoxy)phenyl-2-hydroxy-2-propylketone,2,2-diethoxyacetophenone, 4-benzoyl-4′-methyldiphenyl sulfide, ethyl4-(dimethylamino)benzoate, mixtures of 2-isopropyl thioxanthone and4-isopropylthioxanthone, 2-(dimethylamino)ethyl benzoate,d,l-campherquinone, ethyl-d,l-campherquinone, mixtures of benzophenoneand 4-methylbenzophenone, benzophenone,4,4′-bisdimethylamine-benzophenone, (η⁵-cyclopentadienyl)(η⁶-isopropylphenyl)iron(II) hexafluorophosphate, triphenylsulfoniumhexafluorophosphate or mixtures of triphenylsulfonium salts, andbutanediol diacrylate, dipropylene glycol diacrylate, hexanedioldiacrylate, 4-(1,1-dimethylethyl)cyclohexyl acrylate, trimethylolpropanetriacrylate and tripropylene glycol diacrylate.

The present invention provides use of a composition as described abovefor producing a heat-insulating coating.

The present invention furthermore provides a heat-insulating coatingcomprising at least one oriented, cured layer of the composition of theinvention.

The heat-insulating coating of the invention preferably comprises atleast one IR-reflecting, cured cholesteric polymer which has a helicalsuperstructure which corresponds to a wavelength in the IR spectralrange.

The cholesteric polymer can be obtained, for example, by orienting andcuring a component B from group a), b), c) or d) as described above.

When the heat-insulating coating comprises at least two layers, theIR-reflecting polymers in the different layers preferably each havedifferent helical superstructure pitches which correspond to wavelengthsin the IR spectral range, and/or opposite chiralities (handedness). In aheat-insulating coating comprising at least two layers, it is alsopreferred that the helical superstructure pitch of 2, preferablyadjacent, layers in each case is identical, but their chirality isdifferent. In a heat-insulating coating comprising at least two layers,it is likewise preferred that a medium is present between layers havingan identical helical superstructure pitch and identical chirality whichmedium reverses the direction of rotation of the transmitted circularlypolarized light, in particular what is known as a λ/2 film or plate.

The heat-insulating coating preferably comprises from 1 to 10 layers,particularly preferably from 1 to 4 layers, especially 2 layers. The twolayers preferably differ in helical superstructure pitch or inchirality. It is particularly preferred that the two layers have anidentical helical superstructure pitch, but opposite chiralities.

The present invention furthermore provides a process for producing theheat-insulating coating of the invention, which comprises applying to asubstrate a composition of the invention and, if desired, orienting saidcomposition and curing said composition. Curing is preferably carriedout by polymerizing the monomers of group a) or b) or the solvent ofgroup d) or by crosslinking of the polymer of group c).

Additional layers are produced by repeating the procedure of applying,orienting and curing, preferably using a composition of the inventionwhich is different from the first composition, so that the orientedcholesteric polymers obtainable by polymerizing the monomers of group a)or group b) or the oriented cholesteric polymers of group c) or d) indifferent layers have another helical superstructure pitch and/oropposite chirality to those of the first layer. Alternatively or inaddition, it is possible to introduce a medium between two layers havingan identical helical superstructure pitch and identical chirality, whichmedium reverses the direction of rotation of the transmitted circularlypolarized light, in particular what is known as a λ/2 film or plate.

What was said above with respect to the preferred compositions andheat-insulating coatings applies accordingly.

The substrate is preferably transparent. The transparent substrate maybe, for example, a glass brick, a window pane, an automobile pane or afilm which is to be bonded adhesively to glass for insulation purposes.

The cholesteric IR-reflecting layer can be applied to the substrate bycustomary techniques, for example by means of techniques selected fromfloating knife coating, bar coating, air-knife coating, squeeze coating,impregnating, reverse roll coating, transfer roll coating, gravurecoating, kiss coating, casting, spraying, spin coating or printingtechniques, such as letter press, flexographic, intaglio, offset orscreen printing.

Prior to the application of the composition of the invention to thesubstrate, it can be diluted with any suitable diluent. Suitablediluents are the abovementioned ones.

The IR-reflecting layer(s) applied can be cured thermally,photochemically or by beam of electrons.

Curing must of course take place in the cholesteric phase and withretention of the cholesteric phase.

Where two or more layers are applied, they can in each case be applied,oriented, if desired, dried, if desired, and cured individually.However, it is likewise possible to apply two or more, or all, of thelayers to be applied in one application procedure wet-in-wet to thearticle that is to be coated, to carry out conjoint drying if desiredand then to carry out conjoint curing. A prerequisite for thesimultaneous application of the cholesteric layers, however, is thatthere is no interdiffusion between different layers having a differentreflection behavior.

Casting techniques are particularly suitable for the simultaneousapplication of cholesteric layers, especially knife or bar castingtechniques, cast-film extrusion or stripper casting techniques, and thecascade casting process. These casting techniques are described, forexample, in DE-A-19 504 930, EP-A-431 630, DE-A-3 733 031 and EP-A-452959, which are incorporated herein by reference.

The composition of the invention is particularly suitable for producingprinted insulated windows or heat-insulating transparent constructionmaterials, or for insulating residential, office or industrial buildingsagainst thermal radiation. In addition, the composition of the inventionis also particularly suitable for use in the automotive sector, inparticular for producing heat-insulating printed glass panes. Thepresent invention therefore also provides articles having thereon aheat-insulating coating of the invention.

Owing to the presence of compound A, the heat-insulating coating of theinvention has a tint, preferably a bluish or greenish tint. In addition,compound A advantageously absorbs IR radiation, so that theheat-insulating properties of the coating are enhanced, as unreflectedIR radiation is absorbed and not transmitted.

The heat-insulating coating of the invention exhibits a lighttransmission in the wavelength range from 350 to 750 nm, as determinedin accordance with ISO 9050 of at least 70%, preferably at least 72%.

The examples which follow illustrate the invention without limiting it.

EXAMPLE

A compound of the formula X was used as a nematic achiral polymerizablemonomer.

A compound of the formula XI was used as chiral polymerizable monomer.

Compound A used as a compound of the formula I in which P is aquaterrylimide of the formula II which is symmetrically substituted atthe quaterrylene framework with 6 tert-alkylphenoxy radicals (n=6) andbears no halogen substituents (m=0) and wherein R² is alkyl-substitutedphenyl. This compound is subsequently referred to as Ia.

The solvent used was tetrahydrofuran (THF).

A mixture of the compounds X, XI and Ia, the leveling agent Byk 361 (10%strength; Byk Chemie) and the photoinitiator Irgacure 184 from Ciba inthe concentrations listed in table 1 in 10 g of THF was applied to a PETfilm with a doctor blade in the wet film thicknesses listed in table 1.Upon evaporation of the solvent at about 85° C. a homogeneous,transparent, green-tinted layer formed. This layer was cured by means ofa UV lamp. TABLE 1 Amount Amount Amount Amount Amount (Byk 361)(Irgacure) Example (X) [g] (XI) [g] (Ia) [g] [g] [g] A 1.5 — 0.15 0.50.2 B 4.5 — 0.45 0.5 0.2 C 4.5 0.245 0.45 0.5 0.2

Visual evaluation gave the results shown in table 2. TABLE 2 ExampleLayer thickness [μm] Visual evaluation A 4.0 transparent 5.5 transparent7.0 slight haziness B 3.8 hazy 5.8 increasing haziness 7.1 increasinghaziness C 3.5 transparent 5.3 transparent 6.6 transparent

The visual evaluation was verified by transmission measurements inaccordance with ISO 9050 in the experiments B and C. The results aresummarized in table 3 below. TABLE 3 Example Layer thickness [μm]T_(vis) [%] T_(sol) [%] B 3.8 59.2 51.6 C 3.5 72.8 38.8T_(vis) = transmission in the wavelength range from 350 to 750 nmT_(sol) = transmission in the wavelength range from 350 to 2500 nm

Desired values in accordance with ISO 9050:

-   T_(vis)>70%-   T_(sol)<40%

1. A composition comprising i) at least one radiation-absorbingtert-alkylphenoxy-substituted polycyclic compound A of formula I

where P is a conjugated polycyclic radical which is stable to bases andnucleophiles, optionally bears aryl substituents and contains no groupfrom the group consisting of —CO—NH—CO—, —COOH and —CO—O—CO—; R isC₁-C₈-alkyl, wherein the carbon chain of said C₁-C₈-alkyl may beinterrupted by one or more groups selected from the group consisting of—O—, —S—, —NR¹—, —CO— and —SO₂— and which may be monosubstituted orpolysubstituted by identical or different radicals selected from thegroup consisting of C₁-C₆-alkoxy and a 5- to 7-membered heterocyclicradical which is attached via a nitrogen atom and may contain furtherheteroatoms and/or may be aromatic; or R is C₅-C₈-cycloalkyl, whereinthe carbon framework of said C₁-C₈-cycloalkyl may be interrupted by oneor more groups selected from the group consisting of —O—, —S—, —NR¹—,—CO— and —SO₂— and which may be monosubstituted or polysubstituted byC₁-C₆-alkyl; R¹ is hydrogen or C₁-C₆-alkyl; Hal is chlorine or bromineor mixtures thereof; m is from 0 to 15; and n is from 1 to 16, whereinthe sum m+n is ≦16 and ii) at least one curable IR-reflecting componentB which comprises a) at least one achiral nematic polymerizable monomerand at least one chiral polymerizable monomer; b) at least onecholesteric polymerizable monomer; c) at least one cholestericcrosslinkable polymer; or d) at least one cholesteric polymer in apolymerizable diluent.
 2. A composition as claimed in claim 1, whereinsaid P in said compound A of formula I is a base-stable radical selectedfrom the group consisting of naphthalenes, anthracenes, phenanthrenes,tetracenes, perylenes, terrylenes, quatterylenes, pentarylenes,hexarylenes, anthraquinones, indanthrones, N-substitutednaphthalene-1,8-dicarboxylic monoimides, N,N′-disubstitutednaphthalene-1,8:4,5-tetracarboxylic diimides, N-substitutedperylene-3,4-dicarboxylic monoimides, N,N′-disubstitutedperylene-3,4:9,10-tetracarboxylic diimides, N,N′-disubstitutedterrylene-3,4:11,12-tetracarboxylic diimides, N,N′-disubstitutedquaterrylene-3,4:13,14-tetracarboxylic diimides, acridines, carbazoles,dibenzofurans, dinaphthofurans, benzimidazoles, benzothiazoles,phenazines, dioxazines, quinacridones, metal phthalocyanines, metalnaphthalocyanines, metal porphyrins, cumarins, dibenzofuranones,dinaphthofuranones, benzimidazolones, indigo compounds, thioindigocompounds, quinophthalones, naphthoquinophthalones anddiketopyrrolopyrroles.
 3. The composition as claimed in claim 1, whichcomprises from 0.01 to 20% by weight of said compound A, based on thetotal weight of said component B.
 4. The composition as claimed in claim1, wherein said component B comprises at least one achiral nematicpolymerizable monomer and at least one chiral polymerizable monomer. 5.The composition as claimed in claim 1, which further comprises at leastone auxiliary selected from the group consisting of photoinitiators,binders, leveling agents, UV stabilizers, weathering stabilizers, andmixtures thereof.
 6. (canceled)
 7. A heat-insulating coating comprisingat least one oriented, cured layer of said composition as claimed inclaim
 1. 8. A heat-insulating coating as claimed in claim 7, whichcomprises at least one oriented, IR-reflecting, cured cholestericpolymer which has a helical superstructures pitch which corresponds to awavelength in the IR spectral range.
 9. A heat-insulating coating asclaimed in claim 8, which comprises at least two layers, wherein said atleast two layers each comprise an IR-reflecting polymer having differenthelical superstructures pitches which correspond to wavelengths in theIR spectral range, or opposite chiralities; or different helicalsuperstructures pitches which correspond to wavelengths in the IRspectral range and opposite chiralities.
 10. A process for producing aheat-insulating coating as claimed in claim 7, which comprises applyingto a substrate said composition as claimed in claim 1, and, optionally,orienting said composition and curing said composition.
 11. A process asclaimed in claim 10, wherein said curing is carried out by polymerizingsaid at least one achiral nematic polymerizable monomer and at least onechiral polymerizable monomer; or said at least one cholestericpolymerizable monomer; or said polymerizable diluent, or crosslinkingsaid at least one cholesteric crosslinkable polymer.
 12. An articlecomprising a heat-insulating coating as claimed in claim 7.